I have been using MAC fluidline in Dipdown for years. It dries much darker than you see in the photo and is a lovely very dark brown that really looks good with my blue eyes. Keep the lid on tight and it will last forever.
I've been using this for years and it has never let me down. Best with an angled eyeliner brush, in my experience. It's waterproof and doesn't smudge.. if I go straight from work to the gym I don't have to worry about this sweating down my face.